Complying with CWA Section 316
In October 2007, more than 100 people met at the headquarters of Tri-State Generation and Transmission Association in Westminster, Colo., for an EPRI-sponsored workshop on Section 316(a) of the Clean Water Act (CWA). This section of the CWA regulates the thermal effluents of once-through power plant cooling systems. It provides for variances from both technology-based limits and water quality standards if a plant can demonstrate that its thermal discharge “will assure the protection and propagation of a balanced, indigenous population of shellfish, fish, and wildlife in and on that body of water.” The 316(a) program was very active in the 1970s, when thermal dischargers conducted studies to determine whether they qualified for a variance.
“Even if the Clean Water Act has not changed in 35 years, the world has and continues to do so,” said Dr. Robert Goldstein, a senior technical executive of EPRI. “Water issues such as thermal discharge, impingement and entrainment, total maximum daily loads, effluent guidelines, and availability are converging. We have come together as a concerned community of power plant employees, regulators, consultants, researchers, professors, and students to consider a mixture of old and new topics that excite the imagination and call out for creative scientific, technical, and policy solutions.”
It ain’t broke—it’s just stale. Over two days, attendees heard more than 25 presentations on 316(a) from technical, legal, and regulatory perspectives. Among the technical topics covered were the development of water quality and thermal standards, thermal response characterization, thermal modeling, recent advances in cooling technologies, and the interplay between 316(a) and 316(b).
Some speakers discussed 316(a) from more than one perspective. For example, keynoter Chuck Coutant provided an overview of the past 60 years of attempts to set temperature criteria and standards to protect aquatic life. He pointed out that although regulatory efforts to control potential adverse effects from thermal discharges have been ongoing since the mid-1960s, there is no consistent framework within which states develop and implement protective water temperature quality criteria.
Deborah Nagel, industrial branch chief of the EPA’s Water Permits division, discussed the specific requirements of applications for a 316(a) variance. She also said that, from the agency’s perspective, state permitting authorities are not implementing the section consistently or correctly.
To improve the situation, the EPA expects to update its 316(a) technical guidance document, originally drafted in 1977, soon. “The 316(a) guidance manual has served us well for 30 years, but it is certainly due for updating,” said Chuck Coutant. “The basic structure of using retrospective (no prior harm) and predictive (thermal requirement data for organisms) approaches for demonstrating a balanced community remains strong. But the guidance needs to [reflect] a number of administrative and judicial decisions [since 1977], such as including managed, non-indigenous fish species and not expecting a return to pristine conditions. Also, several indices of community health have been developed that are very useful for evaluating the balance of aquatic communities, which is the crux of Section 316(a).”
While the EPA works toward updating the guidance document, several states are making an effort to revise long-outdated water temperature standards. Presentations by Erich Emery of the Ohio River Valley Water Sanitation Commission (whose members represent Illinois, Indiana, Kentucky, New York, Ohio, Pennsylvania, Virginia, and West Virginia), Lareina Wall of Colorado-based GEI Consultants, and Mike Wenholz of Wisconsin’s Department of Natural Resources discussed the status of updates to thermal standards in their respective states.
Research updates. Several workshop presentations updated scientific research on thermal response characterization. Rob Reash of American Electric Power discussed the issues involved in comparing laboratory and field tolerances for fish. Tamara Pandolfo of North Carolina State University presented her data on freshwater mussel sensitivity to a range of water temperatures, which showed that the presence of a secondary toxicant can make mussels more sensitive to temperature stress. Telemetry and other state-of-the-art tools for evaluating impacts of thermal discharges on fish were presented by Tim Brush of Normandeau Associates.
One-third of the presentations consisted of recent, site-specific case studies. Terry Cheek of Geosyntec Consultants and Bill Evans of Georgia Power described the drivers of Georgia Power’s decision to retrofit the cooling towers of three of its plants to prevent fish kills under extreme conditions, and the implications of doing so on the viability of the 316(a) regulatory option. David Lee of We Energies shared the 316(a) demonstration process, including thermal plume modeling, used to prepare the Oak Creek Expansion Project’s Wisconsin Pollutant Discharge Elimination System (WPDES) permit application.
The conference took on an international flavor as folks from France, the Netherlands, and New Zealand discussed their countries’ plant cooling water policies. Yves Souchon of Cemagref, a French public research institute focusing on land management issues, and Cecile Delattre of Électricité de France presented a summary of the thermal discharge regulations in their nation and some results of biological monitoring at power plant sites. Maarten Bruijs of the Dutch consultant KEMA described a field study on the influence on fish behavior of higher water temperatures in the cooling water discharge of Claus Power Plant in the Netherlands. Finally, Jacques Boubee of the National Institute of Water and Atmospheric Research summarized New Zealand’s generation and environmental regulations and the challenges in meeting them at Huntly Power Station, the country’s biggest thermal plant.
Hot topic. A common theme of many presentations was the effect of climate change on plant environments. For example, Yves Souchon and Cecile Delattre explained that Europe’s heat wave of 2003 raised questions that France’s environmental policymakers are still struggling to answer. As for climate change’s effect in the U.S., Deborah Nagle of the EPA said it was creating more areas with prolonged dry and wet conditions and generally increasing the ambient temperatures of waterbodies.
The workshop closed with several presentations on emerging issues and future research needs. E. Eric Adams of MIT discussed advances in thermal plume modeling. Judson White and John Waddill of Dominion Resources explained the performance rationale for hybrid cooling, called for in their company’s recent COL application for a proposed new unit at the North Anna nuclear station. Tim Hogan of Alden Research Laboratory discussed the benefits of colocating power plants with desalination or liquefied natural gas facilities. In such arrangements, the power plant’s discharge can serve as the water supply for either type of facility, thereby reducing costs and enabling the sharing of research, construction, permitting, and monitoring resources.
The workshop was organized by a steering committee consisting of Chuck Coutant (retired); Doug Dixon and Robert Goldstein of EPRI; Raymond Harrell and Ron Lewis of Duke Energy; Chantell Johnson of the host (Tri-State); Christine Lew and Bill Mills of Tetra Tech; Dave Michaud of We Energies; and Rob Reash of American Electric Power.
EPRI will publish the workshop proceedings early this year. For more information, contact Robert Goldstein at rogoldst@epri.com.
—Christine Lew, PE, a senior enviromental engineer for Tetra Tech Inc. (www.teratech.com).
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